Which physical feature would make the journey from Babylon to Jerusalem a difficult task

The space between Babylon and Jerusalem is a very inhospitable one. Everything is covered with desert, the Syrian Desert to be more specific. It is a very dry, very hot area, with very little water only on few spots. There are sand storms that are very dangerous. This makes this area very dangerous for traveling, so the people mostly avoided traveling through it in order to not end up lost or dead in it. The travelling between these two cities was very limited, and it was mostly done either by circling around this desert, or through very well organized expeditions.